Preselecting mechanism



` mechanismutilizing theminvention;` i: t 1

` i Eig, 2 isantisometric detailof one `of the pre-` ,r `selector assemblies; f f

tion of that, tion of JohnWilliams and Edward J. iMastney, Y SerialNo. 390,514, flledApril 26, 1941 andis an i improvement upon the finventions,disclosed-zand 15 s curate.` i

s s s v, 2,293,355 PRESELECTING MECHANISM s Eloi' B. ,Olson, Chicago,

s l., assignors -`poration `of Illinois ,rpatenttedAugrlg 1942"*` NT OFFICE' i@ and Edward J. Masiney, y `toiOak Mfg.` Co., a cor,V r

This invention `relates to a preselecting incohanisnrand has particular,application,to such de-` vices as` tuning elements ofpradio communication systems and other similar devices. this invention may be`used here any `mechanism or movable memberis to be moved `quickly:` and accurately tto t a preselected `position within a range .of` travel.` The inventionrtmay `be used a wide range of application. ,t i The invention disclosed herein is a :modiiicadisclosed in the copendingrapplicaeither withylocal `orremote control `andrnayuhave s claimed in United., States Patent 2,281,640 toTen Cate and Patent No. 2,161,183uto Mastney, par#` ticularlythe latter. As disclosed in the Mastney `I `In general, ,l

`Fig. 3ds a sectional elevation of one of the preselector assemblies minus the driving gears; ,3 fFig. 4;isaview along 4-4 `of` Fig. 3; and

Figs 5 `is an exploded `sembly l-minus shaft and drive gears.` i t, f

s The mechanism shown inFig. `1 contains three `banks of preselector groups,` the banks being simillar andthe group consisting cfa plurality ofsimpatent, amember to be indexed is positioned. by f the action of opposing` forcesset in motion by opa positely revolving gears or, the like and communir cated to said indexed member through a plurality 0f Coupling means: g r i i In order; to increasethe accuracy` of preselection, it is` possible'to gearup the preselecting icon# ,ilar` `preselector units. Anfzelectric motor III shownliin dotted line, is utilized as` `a `source `of power.` Motor I0 "drives a shaftI Icarrying a pinionfIZ around which banks I3, I 4 and I5 are grouped. The number and arrangement of banks isunimportant. `It, is `understood that the 'api paratusmay befsupported from rigid suDPOrts. s Thus referring to one bank, `as I 3,1 a plurality lof preselecting units are mounted? in tandem. Onlyoneunitwillbe described in detail since the units are duplicated. Themotive power for one complete bank is communicated from pinion I2 to a `gear I1 which' is rigidly fastened to `a length of `gear stock Iii` extending the length ofV the bank Inasmuch as gear stock I8` is one continuous length `onlyfo'rconvenience and could 25 easily be a single gear for each preselector unit,

r trol with relation to thenally preselected shaft.

Assuming that afgangI condenser` in a radio re` s ceiverfis i to tbe controlled, th'e finally preselected shaft range is practically 180,w ABygearing up the control members, as forjexample, 10 to 1"so that the preselectingi members turn overan 1800 rangepand choosing positions on ageared s up shaft,` the accuracy of the system may be greatly increased. `Thus Tif the `geared up "shaft canbe preselected'to within 1 then the condenser shaft may be controlled to within one-tenth of 1, as-

that the gearing -system is acs suming of course In the lMastney` patent referred to` above, the preselecting angular range canjbe increased as r disclosed therein. w For `moderate increases' of the order of `as muchas 3or.r4` to 1,'the means dis closed in `Isaid* patent is leiiectve and simple. However,` if the gearingupfactorfisto jbe larger,

then the system becomes ratherfbulkyfand some-f Whatcumbersm, requiring excessive plunger travel. i

` y gear Il, rotation of gear 3| willreslult` upon s i operation.` Gear 3|` also` meshes with a, gear `32 it will `bereferre'dfto as `gear` I8.y It is understood thatthe variousmembers "referred to,` herein are suitably journalledin endplates.` 3 s 4 Gear I 3 is adaptedfto be engaged by "a pinion ztrotatably mounted o'n a bracketZI pivotally mounted on arod 22. 'Rod 22 `extends the full length of thebank while bracket 2I and pinion 20 are provided foeachpreselector unit. lIt will be noted that bracket! tion 24 adaptedto be attracted toward polepiece 25 of anelectromagnet. `BracketZ'I lsnorm`a1` 1y biased away `from the electromagnet by spring 21."*`Th'e angular travelbf bracket 2| around rod v22 is determined by slotted tail piece` 23 cooperating with a rod 29.`

*Rotatably mountedon rod22 is a gear 3Iwhich" is r preferably always"v in mesh with pinion 2i)` so that when pinion 20 moved into engagement with motor s s rotatably mounted on `a"rod 33`.` Gears"3|` and 32 y In `order to Idevise asimple and effectivemeans for increasing thetravel range of the preselecting I members the inventiorrherein` has beenfprovided.

in section;

" posite speeds.

are "offset along the axis the adjacent gear sections engager lectorunitrhas apairofigea'rs 3I and 32. i j` GearsI and 32 each engage` large gears 34 and :l5` rotatable around a i preselecting shaft 36.", The relativegear ratios and gear sizes are of no` great consequence. It is desired,.however, to turn gears 34 andi?! from motor I0 at equaland op- I` has anl armature borof rotation so that only Each prese-` Largegears 34 and 36 are similar and consist of apertured supporting discs 31 and 38 carrying ring gears 39 and 48, as by riveting or the like. Ring gears 39 and 40 have a series of outer teeth 4I and l2 and inner teeth 43 and M. Outer teeth 4I and 42 are normal gear teeth and mesh with drive gears 3| and 32 in a normalmanner. Inner series I3 and 44 have normal teeth except that between two teeth, as I5 and 46 Vrespectivelyf shallowflocking section '41 is provided. This may be obtained by incomplete tooth cutting. Any other kind of locking means may be used instead.

In orderthat discs 31 and 38 with their ring gears may rotate freely around shaft 36, a pair of sleeves I8 and 60 are provided respectively. Shaft 38 is preferably provided with flats 5i and 82 and the inner surface 83 of sleeves 48 and 50 is shaped to match the shaft section. Thus sleeves 49 and 50 may slide along shaft 38 `but cannot rotate. The outer surface 54 of each sleeve is smooth to provide a rolling surface for discs 31 and 38. l

Ring gears 38 and 46 preferably face each other and between them is a coupling member 60. Coupling member 80 consists of a supporting disc 8| having a central round aperture 82 and carrying a pair of vspur gears 63 and 84on'opposite sides thereof in' planes .parallel to the disc. Any suitable supporting means asy rivets may be used forvspur gears 83 and 64. Gears 83 and 64 each have abuck tooth 85 and 88 with the 'rest ofthe gear teeth being somewhat smaller than warranted by normal inner ring teeth 43 vand 44. The relation of spur gearr83 to the inner series of teethv is such that every tooth on the spur gear will freely engage with all normal gear teeth of inner series I3. Buck tooth 85 however will not clear locking section 41. So that the meshing of buck tooth 86 `between teeth 45` and 48 will result in jamming and cessation of all gear action. The same applies to gear 8l and its cooperating series Il. 1

As is apparent from Fig. 5, aperture 82 in coupling disc 6I is just large enough to permit rotationon shaft 38 providing sleeves l! and 50 -do not clamp disc 8| therebetween. Betweenadjacent assemblies, vseparating washers 68y and 10 having apertures 1I corresponding to the flattened'shaftsection may be provided. Preferably, sleeves I3 and 80 are long enough so that the ring gear assemblies may turn freely thereon, irrespective of whether central disc 8ll is tightly clamped or not. Suitable clamping means may beprovided, as disclosed for example in Mastney Patent No. 2,179,748. A simple clamping means may consist of a rigid sleeve 12 on shaft 38 co- .operating with a movable sleeve 13,.said sleeves both being disposed at the ends of the entire bank-, Sleeve 13 may be moved to exert clamping force on the aligned sleeves of the entire bank after which locking sleeve 13 may berigidly retained in positionv by a set screwA 1I. y

In order to providea large angular operating range for shaft 38, it would be inadvisable to have gear ratio of the inner series of teeth, `as I3, to its cooperating spur gear 83, a whole number. A whole number as the gear ratio will make it necessary toposition the spur with reference to its inner series of teeth. `Thus, if a. whole number is kused'as a gear ratio, the buck tooth will have to be disposed so that it meets the locking section. With a non-integral number as the gear ratio, a locking action will-occur no matter what the relative gear positions are. Furthermore the range will be greatly increased since a locking engagement will occur less frequently. Whatever the angular range of shaft 38 between two locking positions, increased accuracy of preselection may be obtained by having the final shaft range small. Thus shaft 38 may carry a pinion 15 meshing with a large gear 11 whose 'angular range will be the preselection range. This reduced range may be if a condenser for a radio is to be operated,` upon. In practice, gears 15 and 11 should have means for avoiding all backlash, such as are used on condenser drives' in radios now. Thus gear 11 may consist of two flat gears with a spring to cause one ofthe gears to be at an angle to the other.

It is understood that a preselected position for a control unit may be obtained by adjusting coupling disc 8l on shaft 36 ,in such a position that equal and opposite forceson the coupling member will result from the Jamming of the two spur gears and their gears.

What is claimed is: l

`1.v A preselecting mechanism comprising a shaft having a rotational range of over 360, a coupling member normally rigid on said shaft, a drive member rotatable around said shaft on each side of said coupling member, means for rotating said drive members at equal speeds in opposite directions, a gear train between each driving member and coupling member, said gear train including a first gear mounted eccentrically to said shaft and a second gear meshing therewith, said second gear being rotatable around said shaft axis, and means on said two meshing gears for locking said gears together upon the engagement of predetermined gear teeth whereby said drive members will actuate said gear trains until both have reached locking positions and determine a stationary preselection point for said shaft.

2. The structure of claim 1 wherein said locking means on said two meshing gears include mutilated teethy sections on each gear and so designed that gear action occurs at all times except when said mutilated sections engage.

3. The structure of claim 1 wherein said locking means von said meshinglgears 'include a buck tooth on one and a shallow intertooth section on the other. A

4. The structure of claim 1 wherein the rstnamed gear is carried on said coupling member.

5. Thestructure of claim 1 wherein said firstnamed gear is carried on said coupling member and wherein the locking means include a buck tooth on one of said ltwo meshing gears and a shallow intertooth lockingsection on the other gear.

6. A preselecting mechanism comprising a shaft having a rotational range of over 360, a coupling member normally rigid on said shaft, a spur gear carried by said coupling member on each side thereof androtatable about an axis eccentric to said shaft. axis, a gear on each side of said coupling member rotatable around said shaft and meshing with said first-named spur gear, one of said meshing gears having 'a buck tooth and the other of said meshing gears having a shallow intertooth locking section, said meshing gears being adapted to have normal gear action at all times except when' said buck tooth engages said locking section, and means for rotating said second gears in opposite directions until a preselection point is reached. A

7. 'I'he structure of claim 6 wherein said shaft has a plurality of preselecting units, and wherein means are provided for` adjusting lthe rotary position of' each `coupling inember with relation. tosaid shaft,` a a ,-8. A preselecting mechanism comprising a 4 shaft having `a rotational range of` over'p360", `at leastY one preselecting `unit thereon, each pre selecting unit comprising a coupling member normally movable aroundsaid shaft, a pair of `sleeves on said shaft and enclosing said coupling member and adapted to be `pressed together;

p tightly to grip said coupling member to determine Va rigid coupling memberfpositicn onsaid shaft, a spur gear carried by-said coupling member on .each side `thereof` and rotatable around an axis -eccentric to 'said shaft axis, agear for each spur gear meshing therewith. saidsecond gear being freely rotatable around said sleeve, one of said two gears having a buck tooth and the other having a 4shallow intertooth locking `section adapted to lock only `when said buck tooth and locking `section engage, andxneans for rotating said second gears `around said sleeve at equal 10 speeds in opposite directions. f

ELOF B. OLSON.

EDWARD J. MASTNEY. 

